The expression “in the long run” means “over a long period of time” and does not usually refer to long runs, but there are jokes. A marathoner riddle is:
     
Q: Why does someone who runs marathons make a good student?
A: Because education pays off in the long run!
   
The joke was printed in The Sun (London, UK) on July 10, 2003.
 
     
10 July 2003, The Sun (London, UK), “Running joke” by Vikki Orvice, pg. 65:
WHY does someone who does marathons make a good student? Because education pays off in the long run.
       
Google Books
1001 Cool School Yard Jokes
BY Glen Singleton
Heatherton, Victoria, Australia: Hinkler Books
2004
Pg. 96:
Why does someone who runs marathons make a good student?
Because education pays off in the long run!
     
Google Books
Funny Shaped Balls:
The Biggest Book of Sporting Jokes Ever
By Jonathan Swan
London, UK: Ebury Press
2009
Pg. 19:
Why does someone who runs marathons make a good student? Because education pays off in the long run!
 
Twitter
Holabird Sports
@holabirdsports
Have a goodnight everyone! Almost forgot #CJM Why do marathoners make a good students? Because education pays off in the long run!
5:13 PM · Sep 24, 2012·Hootsuite
 
19 July 2014, Gympie (Queensland) Times, “Sport Joke,” pg. 51:
Q: Why does someone who runs marathons make a good student?
A: Because education pays off in the long run!
   
23 August 2015, Sunday Telegraph (Surry Hills, New South Wales), “Laugh Till Your Face Hurts,” pg. 75:
Q: Why does someone who runs marathons make a good student?
A: Because education pays off in the long run!
 
Newspapers.com
29 October 2015, Independent Record (Helena, MT), “The Paw Print” Capital High), pg. A11, col. 1:
Why does someone who runs marathons make a good student?
A: Because education pays off in the long run!
     
Twitter
William Bryant
@williambryant_
Why does someone who runs marathons make a good student? Because education pays off in the long run!
1:38 PM · Nov 13, 2016·TweetDeck
 
Twitter
Ærchie
@archiearchive
Why does someone who runs marathons make a good student? 
Because education pays off in the long run!
7:55 AM · Feb 22, 2017·Facebook
     
Twitter
Timothy Imholt
@TimothyImholt
Why does someone who runs a marathon make a good student?
Because education pays off in the long run.
#DadJokes
2:37 PM · Apr 17, 2020·Twitter Web App
 
Twitter
Shelagh Creegan
@ShelaghAHP
One for @Bartontd and @CalvinMoorley
Why does someone who runs marathons make a good student?
Because education pays off in the long run! #fricomedy #AHPsActive @WeAHPs
#nursesactive #weactivechallenge
3:04 PM · Aug 28, 2020·Twitter for Android